Assigstobs to isttjrnational motor



June 17; 1930. A. F. MASURY E AL v CONTROL FOR DIRECT CURRENT.GE}NERATORS Filed Nov. 28, 1927 6 5- fiwz (allow; 2' I ,MZLWW PatentedJune 17, 1930 UNITED STATES PATENT OFFICE ALFRED F. MAS'UBY AND QUEENEY,OF TEANEGK, NEW

WILLIAM B. JUPP, OF NEW YORK, N. Y., AND FRANK E. SEY, ASSIGNOBF TOINTERNATIONAL MOTOR COMPANY, OF NEW YORK, N. Y., A CORPORATION OFDELAWARE CONTROL FOR DIRECT-CURRENT GENERATORS Application filedNovember 28, 1927. Serial No. 236,058.

of a direct current given characterlstlc generator to produce a ofcurrent output and is of particular importance in connection with drivenby an internal combustion engine in driving a vehicle.

More specifically, the invention deals with the current control of agenerator which supplies currentto a motor for driving a vehicle.

It has been found that during the accelerating period of the vehicle,the generator loads up faster than the engine power increases.

This reduces the maximum acceleration of the vehicle. After theacceleration period has passed, the engine power increases more rapidlythan the generator loads up.

An object of this invention is to an automatic means for controlling t1e pickup of the generator to cause that of the engine, thus obtainingrovide it to agree with the highest possible acceleration.

It is contemplated to provide an improved construction of the abovecharacter for controlling a direct current generator, the fields ofwhich are excited by a differentially wound eXciter, by means of varyingthe excitation of the separately excited shunt held.

In carrying out the above object, a resistance is inserted in the shuntfield of the exciter and is varied by contactors operated uponpredetermined current motor. During acce serted in the field'to flow tothe driving leration, reslstance 1s mreduce the pick-up, and

when the power developed is greater than that necessary for driving theincreasing the generator the same load at a lower sistance is cut out,load, or producing englne speed.

vehicle, re-

Further objects will appear as the description proceeds and referenceWlll now be had, for a more detailed descriptlon of the invention, tothe accompanying drawlng, forming a part hereof, a preferred form of ameans for varying wherein the single figure shows the inventionincluding the resistance in the exciter field by means of seriescontactors 0 erated by the flow of current through the driving motor. I

Referring to the drawing accompanying this specification, G is asuitable generator for driving motor M which serves to drive a vehiclein any manner. The motor is connected in circuit with the generator bymeans of line 21, line 30, motor field m line 28, series contactor Lline 26, series contactor L line 24, exciter difierential field d f andline 22. The generator separately excited field 9 s is connected throughline 1 with the positive terminal of battery B and with the positiveterminal of the exciter through line 3. A resistance B may be providedin parallel with the field g s to change the charging rate of thebattery. Generator separately excited'field winding t 7. is provided forenergizing the generator.

A differentially wound eXciter E is connected to energize the generatorseparately excited field winding 25 f by means of lines 3 and L. Theseparately excited field e of the exciter being connected across thebattery B through lines 1 and 2. A control drum contact 0 is connectedin this field circuit and serves to control the operation of themechanisin.

In order that the excitation of the exciter may be'varied, a resistanceR is inserted in the circuit of the separately excited field e s.Portions 1" and r are connected, through lines 5 and 6 respectively,with the series contactors L and L respectively. These contactors arecontrolled by a predetermined current flow through the generator andmotor circuit, both being energized to insert resistance elements 7'"and 0' in the exciter field circuit due to the heavy current flow instarting and accelerating, but contactor L is designed to drop out whenthe current flow reaches a predetermined value above that of cont-actorL These contactors are so designed that L'drops back and closes thecircuit 5 after the accelerating period of the vehicle has beencompleted. At this time, the generator picks up its load under its own1nherent characteristics until the point is reached where the powerdeveloped is greater than that called for by the vehicle. At this point,contactor L drops back to close circuit 6 and cut out resistance element1' This increases the excitation of the exciter and, correspondingly,the generator shunt field g a, to enable the generator to assume agreater load, the resistance being so des gned that the load thusassumed is in proportion to the capacity of the engine of taking on agreater loa A reverse current relay r c is connected in the line 2 andin circuit with the exciter so that the current through the generatorseparately excited field flows from the negative side of the batterthrough line 2, reverse Current relay 1' a, ine 2 to the negative sideof the exciter, through the exciter and line 3, to the shunt fieldwinding 9 s, and through line 1, back to the batter B. The reversecurrent relay 1- c is pick up as the exciter is started, and serves as aprotection against a reversal of the current through the separatelyexcited field winding.

The operation of the above system will be apparent from the foregoingdescription, and it is to be observed, as noted above, that theresistances r and r are to be designed to cause the excitation of the upits load,throughout practical] the entire operating range in proportionto t e ca acity of the engine for assuming greater oads. The contactorsL and L are designed to drop outat the proper points of the generator toefl'ect its operation inv acgenerator to pick in the power curve.

means to decrease the number of resistance elements in the exciter fieldstill further after the power developed is greater than that called forby the vehicle to cause the generator to increase its load in proportionto the ability of the engine to assume an added load. This specificationsigned this 23rd day of November A. D. 1927.

' ALFRED F. MASURY.

WILLIAM B. JUPP.

FRANK E. QUEENEY.

cordance with the characteristics described above.

We claim as our invention:

In a device including an internal combustion engine, a generator havinga separately excited field for suppl ing power to drive a vehicle,wherein a fiirality of resistance elements are selective y inserted incircuit with said field to vary the excitation thereof in successivestages in accordance with the building up, normal running, and increasedspeed portion of the speed tor ue curve of an internal combustion engineier driving the generator, an exciter for energizing the separatelyexcited field of the generator, a field winding for the exciter, asource of current for energizing the field winding of the exciter, aplurality of resistance elements, automatic means operated b the neratorcurrent to increase the num r 0 resistance elements in the field of theexciter during the acceleration of the vehicle and to decrease thenumber of resistance elements therein after the accelerating period hasceased, to cause the generator to pick up its load in proportion to thatof the engine, and

